Finding the Fourth Proportional to 21,499,123.82, 29,688,507.42 and 13,661,219.30

Step by Step Solution

1. Step 1: Write the proportion equation
   21,499,123.82 : 29,688,507.42 = 13,661,219.30 : x
2. Step 2: Convert to fraction form
   21,499,123.82/29,688,507.42 = 13,661,219.30/x
3. Step 3: Cross multiply
   21,499,123.82x = 29,688,507.42 × 13,661,219.30
4. Step 4: Simplify right side
   21,499,123.82x = 405,581,210,554,297.25
5. Step 5: Solve for x
   x = 405,581,210,554,297.25/21,499,123.82
6. Step 6: Final answer
   x = 18,865,011.15